This invention relates to stabilized aqueous compositions consisting essentially of a sulfonylurea or its agriculturally suitable salt with an effective amount of a salt of a carboxylic or an inorganic acid, or with mixtures of such carboxylic or inorganic acid salts, provided that the solubility of carboxylic or inorganic acid salts at 5.degree. C. and a pH of about 6-10 is greater than or equal to 3% and further provided that the pH of a 0.1 molar solution of the carboxylic or inorganic acid salt is between 6 and 10.
Sulfonylureas, are known in the literature. For instance, U.S. Pat. Nos. 4,127,405 and 4,169,719 teach herbicidal sulfonylureas. The aqueous suspension formulations of these herbicides are stabilized by the technique of the instant invention.
The above-mentioned patents and others disclose sulfonylureas which are highly effective as herbicides. There is however, a need to store agriculturally suitable formulations of such sulfonylureas for long periods of time after they are produced. Maintaining the stability of formulations of such herbicides is extremely important since an unstable formulation will be considerably less effective when utilized. That is to say, the active ingredient must be maintained intact in the formulation if herbicidal effect is to be maximized.
According to the instant invention, a formulation has been discovered, described below, which serves to maintain the stability of sulfonylurea herbicides.